The UK government is currently working on a project called Care.Data that will extract healthcare data from doctor's offices and link it with data from hospitals and other government services. When this project was first announced there was a lot of negative press around issues of opting out of the data collection, informed consent and selling the data to commercial organisations.

Here's an interesting series of videos from The Nuffield Trust showing some of the leaders in this area talking about how we can ensure confidentiality when we start linking together patient-level data: